1. Field of the Invention
This invention relates to a steering and drive mechanism for toy vehicles. More specifically, the present invention provides a toy vehicle in which independent gear trains for wheels on opposite sides of the vehicle are utilized in combination with a reversible motor to either rotate all wheels in the same direction to move the vehicle on a straight line or, by reversing the direction of the motor, to rotate wheels on opposite sides of the vehicle in opposite directions causing the vehicle to turn.
2. Description of the Prior Art
Various forms of drive mechanisms have been proposed for toy vehicles. Some existing systems utilize gearing systems to provide a means to operate the toy vehicle in both forward and reverse directions. U.S. Pat. No. 2,149,180, for example, provides an automatic reversal for a toy vehicle. With that system, when an activating lever forming the bumper of the vehicle meets an obstacle, the lever urges an activating spur which changes the drive train from engagement with one gear into engagement with an oppositely spinning gear causing the vehicle to change its direction. The oppositely spinning gears engage one another and both are driven by a spring mechanism. A major shortcoming of this system is that the direction of the vehicle is changed only when the vehicle strikes an object.
U.S. Pat. No. 4,508,516 discloses a steering system for toy vehicles which also includes a reversible drive The steering system operates by providing a separate electrical motor for wheels on each side of the vehicle. By selectively providing resistance in the circuit of one of the motors, it is possible to operate one motor faster than the other causing the wheels on one side of the vehicle to turn faster than the wheels on the other side. Reversing the polarity of the motors in this system, however, merely causes the vehicle to operate in a reverse direction and does not affect a turning of the vehicle. While this system does appear to provide an effective manner of turning a toy vehicle, it requires the provision of complicated electrical circuitry and of two electric motors. These features make the vehicle relatively expensive and complex.
There remains the need for a steering and drive system for toy vehicles which only requires the provision of a single electric motor. There further remains a need for such a system which is simple in its design and cost effective to manufacture.